Minimally Invasive Vertical Deep-Sea Mining

Future demands for rare earths and elements such as copper and cobalt, will require an increasing amount of mining operations. While many deposits are found onshore, endeavours to mine offshore, in deep-sea areas become increasingly relevant to sustain market demands. Here, elements are prevalent in massive sulphide deposits formed from dissolved elements settling on the seabed after being emanated from black smokers. Found at depths of 1,000 to 4,000 m, mining these deposits is challenging not only from a technical perspective but also with regard to its environmental impact. This project investigates the effects of sedimentation caused by a newly developed vertical sea bed trench cutter. It aims to mine sulphide ores as environmentally friendly as possible by identifying minimally invasive ways of sulphide extraction. As fine-grained deep-sea sediments are not readily available in large quantities, substitute sediments suitable for experimentally investigating the sedimentation process must be identified. Therefore, different off- and onshore sediment samples are analysed and compared regarding their grain size distribution and sedimentation rate. Experimental investigations are carried out in a small test tank examining the threshold values of sediment particle migration.